A huge manhunt is underway in Southern California. People are looking for a former LAPD officer said to be armed and extremely dangerous.

CHIEF CHARLIE BECK: Christopher Dorner is wanted for a series of crimes, including assaults on officers and three homicides in Southern California in the past week.

SIEGEL: That's Los Angeles Police Chief Charlie Beck briefing reporters today. Beck says Dorner shot three officers, one fatally, early this morning. He's also believed to be responsible for the murder of two people this past weekend, all part of a vendetta against law enforcement outlined in a manifesto posted online.

NPR's Kirk Siegler is covering the story and joins me now. And, Kirk, what more do we know about this man, former LAPD Officer Christopher Dorner?

KIRK SIEGLER, BYLINE: Well, Robert, he's 33 years old. He's also a former Naval Reserve Officer. And he was on the LAPD force from 2005 to 2008, when he was fired for making false statements. Now, police say he made up a story about a fellow officer using unnecessary force against someone. Now, Dorner writes at length about this in his disturbing manifesto in which he vows to kill LAPD officers and their families until his name is cleared.

Now, Robert, we're also learning tonight that he sent a package to CNN's Anderson Cooper in New York back on February 1st. And that package contains a note, a DVD and a ceremonial coin awarded to LAPD officers that appears Dorner got from former LAPD Chief William Bratton. Now, that coin has bullet holes throughout it. Now, Dorner himself is believed to be heavily-armed and dangerous, and this is of course why police are reacting as they are.

SIEGEL: And what is the LAPD doing to protect officers and also to find this man?

SIEGLER: Well, specifically, the LAPD has 40 different protection details at different locations around the LA area. These are at sites where authorities believe their officers and their families are most at risk from Dorner. It was actually at one of these protection details early this morning in the city of Chino, east of Los Angeles, where officers were protecting one of the people mentioned in Dorner's manifesto.

They say Dorner arrived firing at them. No one was seriously hurt and he sped away in his pickup. But a short while later, according to police, Dorner shot and killed one police officer in nearby Riverside and critically wounded another. They were on a routine patrol.

Now all of this, Robert, follows that double homicide down in Orange County this past weekend. Police say Dorner killed a couple sitting in their car in a parking garage at their condo. Now, the female victim was an assistant basketball coach at Cal State Fullerton. And police say she was also the daughter of the former LAPD captain who actually represented Christopher Dorner during those disciplinary hearings that led to his firing back in 2008.

SIEGEL: And I understand that some people who were completely unconnected to Dorner were also injured in all of this. What happened there?

SIEGLER: Yeah, I mean the scope of all of this is really amazing. I mean, in that incident, you mention that occurred early this morning in Torrance, California, police were on one of their protection details. They saw a vehicle they thought matched the description of Christopher Dorner's.

They fired on it. Turns out the two occupants were civilians, reportedly delivering newspapers. They were taken to a local hospital. One is in stable condition, the other was expected to be released.

SIEGEL: Are police giving any sense as to where they think Christopher Dorner may be or how close they are to finding him?

SIEGLER: Not yet, Robert. I mean, it's been a wild day, I can tell you that. The latest that we know, police have narrowed their search, it appears, into the San Bernardino mountains above Los Angeles, where they're investigating a scene of where a vehicle that matches the description of Dorner's is located. TV footage is showing a truck that's burned out in a snowy pine forest in the woods. Schools in that area were on lockdown and the ski resorts there closed. Now, earlier in the day, there was another big scene, though, with authorities responding to the Point Loma Naval Base down in San Diego, where Dorner apparently stayed, but nothing concrete there, either. So, that's 150 miles from where authorities are now investigating his truck. That gives you an idea of the scope of all this.